Abstract

Nanostructured α-Fe2O3 thin film electrodes were deposited by aerosol-assisted chemical vapour deposition (AACVD) for photoelectrochemical (PEC) water splitting on conducting glass substrates using 0.1 M methanolic solution of Fe(acac)3. The XRD analysis confirmed that the films are highly crystalline α-Fe2O3 and free from other iron oxide phases. The highly reproducible electrodes have an optical bandgap of ∼2.15 eV and exhibit anodic photocurrent.

The current–voltage characterization of the electrodes reveals that the photocurrent density strongly depended on the film morphology and deposition temperature. Scanning electron microscopy (SEM) analysis showed a change in the surface morphology with the change in deposition temperature. The films deposited at 450 °C have nanoporous structures which provide a maximum electrode/electrolyte interface.

The maximum photocurrent density of 455 µA/cm2 was achieved at 0.25 V vs. Ag/AgCl/3M KCl (∼1.23 V vs. RHE) and the incident photon to electron conversion efficiency (IPCE) was 23.6% at 350 nm for the electrode deposited at 450 °C.